In patent Abstracts of Japan JP 63134020 A, a ceramic filter element for an exhaust gas filter in an internal combustion engine is disclosed that is constructed of a corrugated spirally wound filter web. For producing the filter web, heat-resistant inorganic fibers are mixed in aqueous suspension with ceramic powder and processed to a web. Several stacked webs are rolled to the desired shape of the filter body whereby between neighboring filter webs honeycomb-shaped flow passages are formed. The filter body is subsequently fired at high temperature.
WO 2006/005668 discloses a method for producing a ceramic filter element in an exhaust gas filter for internal combustion engines. In this connection, first a combustible non-ceramic support web is impregnated with a ceramic slip and, subsequently, burned out in the desired geometric shape until the support web is combusted and a rigid filter body is generated.
In this method, the wall thickness of the finished ceramic substantially corresponds to the thickness of the support web. Likewise, by means of the structure of the base paper, the porosity of the ceramic is influenced.
A disadvantage of the disclosed method is that no filter elements with variable wall thickness, porosity and cell density can be produced.